I got this from a lighting contractor when I got some of my lights, I don't know where you could get one from. I was made by "Ledtronics" which is still around but from their website I didn't see any of these.
I couldn't find them either. This must have been discontinued. The other ones look like they fit the M250R2 and 115 exactly, so it wouldn't work. Does this have a model #?